Azolla (Azolla spp.) – Mosquito Fern
Azolla is a tiny, fast-multiplying floating fern known for its soft, overlapping leaves that change from green to deep red under strong light. It's commonly used for surface coverage, nitrate absorption, and as a natural algae deterrent. Though more popular in outdoor ponds, it can be used in aquariums with low surface flow and adequate trimming.
 
Growth Spread: Floating; forms thick mats
Tank Size: Any (best in low-flow or open-top setups)
Care Level: Easy
Lighting: Medium to high (strong light enhances red tones)
CO₂: Not required
Propagation: Self-replicating—splits and spreads quickly
Notes: Can block light if unchecked; excellent for shrimp tanks, fry protection, and outdoor water gardens; remove excess to prevent oxygen depletion
 
Price is per handful.